"Giant Ragweed"

Ambrosia trifida L.

Sunflower family (Asteraceae)

bulletDifferent from Common Ragweed in that the leaves are not finely divided...they are large flat, blades with 3-5 lobes
bulletFound in same habitats and season as Common Ragweed
bulletCan be taller than Common Ragweed

Couple nice photos

Vermont site with photos

Rutgers Univ: Giant ragweed

Giant ragweed close-ups